A crate on a floor. Give it a push and it slides — slowing the whole way — until friction drags it to a stop. The rougher the floor, the sooner it stops.
Stop on the mark
The green mark is where it should come to rest. Push just enough so the crate slides up and stops on it. Too little and it stops short; too much and it slides past.
Three worlds
Floor — set how rough it is. Ramp — push up a slope; gravity helps friction stop it. Ice — almost no rub, so it glides on and on.
Watch teaches
Watch isn't free play — it runs set demos and names the physics, even two floors side by side to show smooth vs rough. Game is your try. Practice lets you move the mark.
Learn when you ask
It slides to a rest and sits a moment. When you want the why — friction, the drag, the stopping distance — tap 🔬. The science comes only when you ask.
🟢 Real physics · Friction
What just happened
Just now
Why
The rule
Try it
A Lab of Motion
The Push.
Watch — set demos that show it and name the physics.
Demo 1 of 3
Push strength20
How hard you shove it. Harder push = farther slide.
Roughness25%
🎯 The markdrag on the floor
Tap the floor to move where the crate should stop.